There may be options besides reducing the complexity of your skeletons. If you have many skeletons, it may be acceptable to only update a subset of them each frame, in a round-robin fashion. Another option may be to only animate a small number of skeletons and use those poses to render a larger number of skeletons.
@rongyu Sorry to hear that the documentation section was unclear. This section describes that you could update your skeletons e.g. every second or third frame instead of every frame. Updating them in a round-robin fashion means updating them like this:
// with three skeletons:
1, 2, 3, 1, 2, 3, 1, 2, 3, ..
The last two sentences mean that when animating e.g. a crowd in a stadium, you could animate only e.g. 5 skeletons each frame and re-render the same 5 meshes as an identical duplicate 100 times. When using the spine-unity runtime, there is the RenderExistingMesh component available for such a purpose.
